Power transmission



Feb. 22, 1944'. H. w; GILFILLAN POWER TRANSMISSION Original Filed Sept.20,' 1940 :s v.sheets-sheet 1 INVENTOR ATTORNEYS- Fb- 22, 1944- l-L w.GILFlLLANy POWER TRANSMISSION Original vFiled Sept, 20, 1940 :ssheets-sheet s /lll/IIIIII., l//

' ATTORNEYS.

Patented Feb. 22, 1944 POWER TRANSMISSION Henry W. Gilfllan, Detroit,Mich., assigner to Chrysler Corporation, Highland Park, Mich., acorporation of Delaware Original application September 2), 1940, SerialNo. 357,528. Divided and this application January 23, 1942, Serial No.427,859

(Cl. 'lli-473) 7 Claims.l

This invention pertains to automotive power transmissions and thisapplication is a division of co-pending application, Serial No. 357,528,filed September 20, 1940, by Henry W. Gilllan and Edgar L. Bailey.

The aforesaid joint application relates to a power transmission of theelectrodynamic type wherein a planetary gearset is disposed incombination with electromagnetic brake and clutch devices of the eddycurrent type; the arrangement being such that torque multiplication isobtained through the planetary gearset for starting and acceleration ofthe vehicle, the sun gear being held against rotation by operation ofthe eddy current brake, while the planetary gearset is locked up in oneto one ratio at the end of the acceleration period by operation of theeddy current clutch, suitable control mechanism being provided.

It is the principal object of the present invention to provide in anauto-matic power transmission of the aforesaid type improved manualcontrol means for the shiftable members.

Other objects and advantages cf the invention will become apparent fromthe following description.

In the drawings which accompany the description, and which illustrates apreferred embodiment of the invention,

Fig. 1 is a diagrammatic showing of the power plant and drive mechanismof a vehicle incorporating the present invention.

Fig. 2 is a side elevation of the power` plant and transmissionmechanism,.parts being broken away to show details thereof.

rear gearbox unit of the transmission.

Fig. 8 is a sectional View along line 8 3 of Fig. rI.

Fig. 9 is a diagrammatic view on a reduced scale of part of the Fig. 8shift mechanism, the

view being taken as indicated in the arrows 9 9 on Fig. 8 and the partsbeing shown in neutral position.

Fig. 10 is a view of the Fig. 9 parts in one of their shifted positions.

Fig. 11 is a wiring diagram of the transmission.

Lil)

mitted from shaft I5 to shaft 22.

Fig. 12 illustrates a mdication of the wiring diagram of Fig. 11.

Referring to the drawings wherein reference characters are used todesignate corresponding parts referred to in the following description,Fig. 1 illustrates a typical arrangement of transmission mechanism in avehicle embodying the present invention. The vehicle engine A is coupledto the driving wheels l0 of the vehicle through a pair of torquemultiplying units B and C; the unit B consisting of an electricallycontrolled underdrive unit illustrated in detail in Fig. 2 and the unitC consisting of a manually controlled high, low and reverse gearboxillustrated more fully in Fig. '7. The output shaft ll of unit C isconnected ,by means of the usual propeller shaft l2 with thedifferential gearbox I3, which in turn, drives the axle shafts It.

Referring for the moment to Fig. 2, it will be seen that the enginecrankshaft l5 carries a iiywheel l to which is fastened a driving memberil. The latter forms part of an electrical eddy current clutch whichalso includes a driven member I8 and a coil IS'. The driven member i3 isalso adapted to cooperate with an electrical eddy current brakegenerally designated by 20, and which includes a coil 2|.

The -output shaft 22 of the electrical unit is connected to the flywheelI6 by means of a planetary gearset 23 and the aforesaid driven member i8acts as a drive control element for the gearset. The arrangement is suchthat when the brake coil 2l is energized, the sun gear is held againstrotation and a reduction drive is trans- When the clutch coil I9 isenergized and coil 2l de-energized` a substantially 1 to l ratio driveis transmitted between shafts l5 and 22.

For a more complete description of the electrical unit reference shouldbe made to the aforesaid Gilllan and Bailey application.

Referring now to Figs. 1 to 10, inclusive, it will be seen that theshaft 22 extends rearwardly into the housing 'I4 of the gearbox C inwhich it terminates in a cone-shaped clutch portion l5. A hollow portion'i6 provides space for the roller bearing 'il which pilots the forwardend of the tail shaft ll. Lubricant is circulated through the gears,bearings, etc., through suitable holes which connect with the centralbore 18 of shaft l l.

The pinion 28 is the input element of the boX C and meshes with a gear19, the latter being one of a cluster rotatably carried on acountershaft 80. The cluster also includes a gear 84 which meshes withthe low speed driven gear 8,2, and a gear which is adapted to be engagedby an idler gear 85 for providing reverse drive, the gear 85simultaneously meshing with the gear 83 and a gear 84 splined at 85 onshaft I I.

The shaft 22 is formed with a set of clutch teeth 8l which are adaptedfor engagement by complementary internal clutch teeth 38 formed inclutching sleeve 89, the latter being slidable on a hu'b 90 which issplined at 9| on shaft Suitable blocker synchromesh mechanism 92 isprovided to facilitate smooth and noiseless engagement of the sleeve 89with the teeth 8l. Inasmuch as any suitable type of blocker synchromeshmay be used, this part of the mechanism will not be described in detail,it being deemed sufficient to briefly refer to the salient partsthereof.

A similar blocker synchromesh mechanism 53 is provided for facilitatingmeshing of the teeth of sleeve 89 with the clutch teeth 94 formed onlowspeed gear 82. v

The mechanism for shifting sleeve 89 and idler gear 85 to provide twoforward speeds and reverse comprises a hand actuated lever 95 (Fig. 4)having a knob S at the outer end thereof. The lever 95 is carried by acasing 94 which forms part of .f

the steering column referred to generally by the numeral 98. The Casin-g94 has separable sections for purposes of assembly and a slot isprovided for receiving a ball-shaped enlargement 99 of lever 95. bore|00 in which a spring pressed detent |0| is disposed. The detent I0| isadapted to engage in an aperture formed in the wall of the slot as shownin Fig. 3.

The steering column includes an outer tube |03 on which the casing 94 ismounted, and an inner tubular steering shaft |04 which carries thesteering wheel |05. A tubular shaft |06 extends longitudinally of thecolumn and is slidably and rotatably supported by the column structure.Mounted in the upper end of the tubular shaft |06 is a sleeve |01, whichis welded thereto and extends beyond the upper extremity thereof. Acollar |08 is rigidly secured in place on the shaft by a nut |09. Thecollar |08 is provided with bosses for receiving pins ||0 which arecarried by the forked inner end portion of the lever 95. The enlargedportion 99 of the lever serves as a fulcrum about which the lever may beoscillated in a vertical plane to shift the shaft |06 vertically of thesteering column. The shaft |06 may be rotated about its axis which iscoincident with the longitudinal axis of the steering column by swingingthe lever 95 about the axis of the column.

Axial movement of the shaft |06 is transmitted to the selector mechanismin casing '|4 by a Bowden wire assembly generally designated by numeralIII. One end of the Bowden assembly is mounted in the lower portion of aseparable coupling II2 by means of which an extension ||3 of the columnhousing 98 is supported. The lower element of the coupling ||2 isprovided with an apertured ange I|4 in which a metal tube H5 is fixed bymeans ofa threaded fitting H6. Slidably carried in the tube is a plungerHOI- mally urged upwardly of the column by a spring I I 8 which bearsbetween the plunger and a tting IIS. A flexible cable extends throughthe plug IIS and is attached to the plunger ||7. The latter bearsagainst a plate 2| non-rotatably fixed on the lower extremity of theshaft |06 and which extends outwardly of the coupling ||2 through a slot|22 in the side thereof, the slot being approximately twice as wide asthe 4thick- The portion S9 of the lever has a I ness of the plate I2|for accommodating shifting thereof axially of the column.

The opposite end of the Bowden wire assembly extends to the cover plate|23 of the housing 14 5 where it is received by a fitting |24, theexible cable |29 being attached to a lever |25 swingably mounted at |26.It is apparent that .reciprocation of the shaft |06 will causecorresponding swinging of lever |25, the motion being transmitted by thecable |20.

Rotative movement of the shaft |06 is transmitted to a shift lever |2`|by means of a pair of links |28, |29 connected by a bell crank |30, thelink |28 being pivoted to the plate I2| by means of a pin |3I. The plate|2| has a cam shaped portion I 33 against which a plunger |34 of aswitch |35 is adapted to bear. The switch has a pair of terminals |38,|39 which are adapted to be bridged by the Contact member |40 uponmovement of plunger |34 under the influence of spring |36 when the plateI2| is in certain positions as will be more fully explained.

The cover H23 (Fig. 8) is provided with a pair of aligned bosses |40A,|4| in which is mounted a rock shaft |42, a set screw |43 holding itagainst displacement. The shift lever I2'| is operatively secured on thetop of the rock shaft by a nut |44.

Rockably mounted on shaft |42 is `a trunnion element |45 having anintegral shift finger |46. The element |45 is rockable about a mountingpin |47 and is biased to the position illustrated by a coiledcompression spring |48.

The sleeve 89 and gear 85 are shifted by a pair of shifter forksdesignated |49 and |50 respectively, these forks being carried by a pairof shiftable rails |5| and |52. The rails are provided with the usualinterlocking plunger |53 and detent receiving grooves |54 as illustrateddiagrammatically in Figs. 9 and 10.

The shift finger |46 is normally maintained in engagement with the fork|49 by the spring |48, thus the shift mechanism is normally conditionedfor effecting a shift of the sleeve 89 upon swinging of the lever 95about the axis of the steering column. In order to shift the reversegear 85 it is necessary to disengage the nger |46 from the fork |40 andengage it with the fork which is accomplished by rocking the lever 05upwardly resulting in downward movement of plate I2| tothe dotted lineposition of Fig. 5. This movement of the plate I 2| transmits a push toselector lever |25 through the Bowden cable |20. The selector lever |25is connected inside the casing 'I4 by means not shown with a lever |55which is adapted to push downwardly on finger |48 in response tocounterclockwise swinging of lever |25, thereby rocking trunnion member|45 about the pin |4'| and against the compression of spring |48. The1inger |46 is thereby disengaged from fork I 49 and engaged with fork|50 and swinging of the lever 95 away from the driver will rock shaft|42 about its axis and shift idler gear 85 into mesh with gears 83 and84. Upon return of lever 05 to neutral position, spring |48 will returnthe parts to the position shown in Fig. 8 and the shift mechanism willagain be conditioned for shifting sleeve 89 into engagement with directdrive clutch 81 or low speed drive clutch 94 depending upon thedirection of swing of lever 95.

From Figs. 8, 9 and 10 it may be seen that the portion |50 of the shiftfinger |46 which engages the fork |49 is cam shaped and the slot |51 ofthe fork which receives the portion |56 Iis large enough to permit aconsiderable amount of lost estates motion of finger` |46 before thefork is shifted. 'Ihis is for the purpose of permitting the lever 95 tobe moved back to neutral position from high or low speed positionwithout necessarily moving the sleeve 89, thereby opening the 'switch|35 (because of the action of the cam |33) without ment of finger |45downwardly will automatically cause rail I5| to be returned to neutralbecause of the engagement of the cam portion of the iinger M5 with theright hand projection |56 of fork M9. These projectionsv are provided ineach side of slot |51 as illustrated and function to return rail I5| toneutral whenever the finger |45 is moved to engage the fork |50. Thisoperation will be more fully explained below.

Referring now to 11, it may be seen that eld coils I9 and 2| areconnected to the vehicle battery |59 through a plurality of controlinstrumentalities which include a governor controlled switch |55, anaccelerator operated switch |5| and a pedal operated rheostat switch|62, in addition to the aforementioned switch |35 which is operated bythe plate I2|. v

The switch |55 is operated by a governor mechanism |63 of any suitabletype driven by a shaft itil from the countershaft cluster gear 53, andis provided with two sets of terminals adapted to be bridged by aconductor element |54. When the switch |55 is in low speed condition, asin- Fig. 1l, underdrive coil 2| is connected to battery |55 throughwires |51, |58, element |54, wire |59, switch |52, wire |15, switch |35and wire |1|. The rheostat switch |62 is operated by a pedal |12, whichis equivalent in its operation to a conventional clutch pedal. Theswitch is on` when the pedal |12 is released and off when the pedal isfully depressed, intermediate posi-v tions of the pedal causing varyingamounts of resistance to be introduced into the circuit as can bereadily understood from Fig. ll.

When switch |55 is in high speed position, coil 2| may also be energizedthrough switch |B| which is operated by the accelerator pedal |13. Thelatter is pivoted at |14 to the Vehicle oor board |15 and is urged tothrottle closed positionby spring |15. nects the pedal with a lever |18pivoted at |19 to the lower surface of the floor board. A link |80transmits swinging motion of lever |18 through a suitable lost motionconnection to a throttle valve control lever |82. The latter is adaptedto be swung about its pivot until it engages the stop IBLl carried bycarburetor riser |83 at which position the throttle valve is wide open.The pedal |13, lever |18 and linl; |80 are then adapted to have furthermovement overtraveling wide open throttle valve position which ispermitted by compression of the spring |85y of the lost motion connector||`||.l This cvertravelling movement operatesto swing lever |36, whichis xed to lever |18, far enough for finger |89 thereof to engage theoperating ringer |31 of switch |5| whereupon the switch is closed,thereby completing a circuit from coil 2| to battery |59 through wires|51, ISI, terminals |92, |83 of switch |50, wire |59, switch |62, wire|10, switch |35 and wire |1I. a

Whenever switch |6I is closed by the aforesaid overtravel movement ofpedal |13, itstay's closed until the pedal is returned substantially Alink |11 con-.

Til

to throttle clodpo'sition.- This diie ttl'i.

fact" thatlswijten nel is ef the snap-over' type and :linger oflever |86is purposely positioned so that it will not engage the switch operatingfinger' I811l1`nt`il the accelerator pedal |13` is fully released.Operation of switch I||| by overtravel operation of the acceleratorpedal is' commonlyl referred to/ as kickdown operation. I

vThe switch |6| is of the double pole, double throw type and when it is;open with respect to underdrive coil 2| it is closed' with respecttodirect drive coil |S. The latter is connected to the battery |59throughV wire |94, switch |6I, wire |9|, switch |55, wire |65, switch|52,wire |10, 'switch 35 and wire I1 The battery is grounded at and isshunted by th'eusual generator |56. Fig. '12 illustrates a modificationof the Fig. 1l control circuit, wherein'the circuit is altered bysubstituting agovernor controlled rheostat switchv |62 yfor the pedalcontrolled s'witchhl52. In the Fig. l2 modification, the switch |52 isexactly the sarne in construction and operation'except that it isautomatically operated by' agovernor |91. The latter is intended to bedriven by the engine A in any suitable-(manner, for example, by thegenerator drive shaft, and functions to open the circuit between 'wires|59 and |19 gradually when the vehicle comes toa stop and to graduallyenergize coil 2| when the vehicle is started. If desired as a safetyfeature, the regular vehicle ignition switch may be inserted vin theAcircuit of coils I5 and 2| to thereby renderrthe circuits lth'ereto'deadunless the ignition switch is 011.

This feature is omitted from the drawings for the sakeof simplicity.

In describing the operation of the drive, let

mesh the teeth thereof with clutch teeth 92| of low speed gear 82. vAtthe same time the` accompany-A ing movement of plate |25 permits plunger|34 of switch |35 to move upwardlyl of` Fig. 5 under the iniiuence vofspring |35, thereby to bridge switch terminals |38, |89. The cam |33 ofplate |2| is so designed that the plunger |34 of switch |35 will be heldin switch-open position until the plate |2| has been swung suiii'cientlyto fully engage the sleeve 89 with the clutch teeth 94 or the clutchteeth 81, as thecase may be. 'This feature makes it possible to shiftthe sleeve 89 without clashingv of teethy and without the necessity ofdepressing pedal |12.

Shifting of sleeve 8S `then into low speed position causes switch |35 toclose, thereupon energizing underdrive coil 2| through wiresy |51, |53,terminals |65, |65 of switch |65, wire |55, switch |152, wire |15,switch |35 and wire |1I. Under these conditions, the rheostat switch |52is in the Fig. 11 position with all of the resistance cut outapproximately 7 M; P. H. the governor mechanism |63 will operate to openthe circuit between terminals |65 and |66 of switch |66 and close thecircuit between terminals I 92 and |83 thereof. This action of governor|63 will cause underdrive coil 2| to be de-energized and direct drivecoil I9 to be energized through wire |94, switch I6I (which is in closedposition with respect to coil I9), Wire |9I, switch |69, wire |69,switch |62, wire |16, switch |35 and wire I1I. Theunderdrive mechanism Bis now operating in direct drive with the planetary gear set 23substantially locked up in one to one ratio. This corresponds to secondspeed position in conventional transmission mechanisms.

Direct drive in gear box C corresponding to third speed position inconventional transmission mechanisms, may now be obtained by swinginggear shift lever 95 about the axis of the steering column toward thedriver. As the lever 95 is swung backwardly, theplate I 2| moves plunger|34 of switch |35 to switch open position, thereby de-energizing bothdirect drive coil I9 and underdrive coil 2|. At the same time sleeve 89is moved out of engagement with clutch teeth 94 and into engagement withclutch teeth 81, thereby stepping up the driveratio in gearbox C.-Inasmuch as both coils I9 and 2| were de-energized by the action of thecam |33 during the time that the shift of sleeve 69 was being made, theload was relieved momentarily from the shaft 22, thereby permitting thesleeve 89 to be shifted without the necessity. of depressing pedal |12.When the shift lever 95 reaches the extremity of its movement to highspeed position, which, it would be pointed out. includes the movementnecessary to take up the lost motion on finger |46 with respect to slot|51 of shift fork |49, plunger |34 of switch |35 is again permitted tomove to switch closed position under the action of the spring |36 andunderdrive coil 2| is again energized. Governor operated switch |69having again returned to its low speed position during idling of engineA, the vehicle is now in underdrive in unit B and in direct drive ingearbox C. This corresponds to third speed position in conventionaltransmissions.

The car may now be accelerated to a speed of approximately 18 M. P. H.lwhen governor mechanism I 63 will operate to open the circuit betweenterminals |65, |66 of switch |68 and close the circuit between terminals|92, |83 thereof, whereupon underdrive coil 2| will be deenergized anddirect drive coil I9 will be energized in the manner, explained above.ernor mechanism |63 operates at a higher vehicle speed when gearbox Cisin high speed position due to the fact that the governor is driven from.countershaft cluster gear 83 which, of course, rotates slower whengearbox C is in high speed position for a corresponding car speed, thediilerence in speed being in accordance with the step-up in ratio. Thevehicle under these conditions is being driven in direct drive in bothunits B and C, this condition being equivalent to overdrive inconventional transmissions. It is intended to provide a rear axle ratioof approximately 3.2 to 1, thereby obtaining the advantages usuallyobtained by the use of an overdrive mechanism. v

With such a rear axle ratio it is, of course, obvious that theaccelerating characteristics of the car will be sluggish and provisionis made for an instantaneous return to under drive in unit B when rapidacceleration is desired as, for ex- The govample, when passing cars atspeeds above the operating speed of governor |63 or when climbing hills.

Return to underdrive in unit B is accomplished by kickdown operation ofaccelerator pedal |13. Depression of the said pedal beyond wide openthrottle position compresses the spring |65 of the lost motionconnection |8| and permits movement of lever |18 sumciently to swinglever |86 to such position that the finger |89 thereof engages theoperating finger |81 of switch I6I. Movement of the nger |81de-energizes the direct drive coil I9 by opening the circuit betweenwires |94 and I 9| and at the same time energizes underdrive coil 2|through wires |61, |9I, terminals |92, |63 of switch |69, wire |69,switch |62, wire |19, switch |35 and wire I1I. After the vehicle hasbeen accelerated to the desired speed, return to direct drive conditionis made by releasing accelerator pedal |13 which will `return tothrottle closed position under the influence of the spring |16 whereuponthe finger |99 of lever |86 will engage the operating finger I 81 ofswitch |6| to thereby open the circuit between wires |94 and I9I andclose the circuit between wires I 61 and |9I.

When the vehicle is brought to a stop, the governor mechanism |63 willoperate at a speed of approximately 10 M. P. H. to open the circuitbetween terminals |92, |83 of switch |63 and close the circuit betweenterminals |65, I 66 thereof. This will cause unit B to return tounderdrive condition of operation and the vehicle may be brought to astop by application of the brakes with the gear shift lever 95 remainingin high speed position. The governor mechanism |63 operates to returnthe unit B to underdrive condition at a slower speed than is the casewhen the change is made from underdrive to direct in unit B because ofthe lag which is inherent in most governor mechanisms when speed thereofis reduced. This condition is a desirable one because is it not desiredto change to underdrive in unit B at a speed higher than approximately10 M. P. H. In some cases it might be desirable to further reduce thisspeed in order that change to underdrive in unit B will not take placeevery time the vehicle is slowed down in traic unless it is slowed downto an extremely slow speed which requires the use ofthe underdrivemechanism to obtain a Smooth pick up to cruising speed.

If the vehicle remains at rest with the gear shift lever 95 at highspeed position, there will be a creeping tendency due to the vfact thatcoil 2| remains energized and the amount of torque developed by theengine at idling speed thereof is being transmitted to the tail shaftII. This creeping tendency may be overcome by moving the gear shiftlever 95 to neutral position thereupon de-energizing coil 2| through theaction of the switch |35. This last action may be accomplished withoutdisengaging sleeve 89 from clutch teeth 81 because of the movement ofthe finger |46 permitted in the slot A|51 of the fork |49 withoutcausing shifting movement of the fork |49 or rail |5|. Thus the vehiclemay remain at rest with the rear gearbox C in direct drive condition andthe coils I9 and 2| de-energized. The vehicle may be started from restsimply by movement of the gear shift lever 95 to high speed position,which action is accomplished quickly and easily by a flick of the ngerwhereupon coil 2| will be energized and the vehicle may be acceleratedsmoothly with the unit B operating in underdrive and the unit C indirectdrive. When predetermined speed has been reached a change directdrive in 'unit B will beac'coinplished by operation of theV governorswitch |60; as described'above.

The car may also be held at rest without creep with the sleeve B9engaged and the gear shift lever 95 in high or low speed position bydepress ing the'pedalV |12 to the extent of its movement whereupon theswitch |62 will be opened and the coil 2| def-energized. Switch |52 isparticularly useful whe'nthe car vis being maneuvered at relatively slowspeeds, for example as when parking. By manipulation of pedal iii theresistance in theelectrical circuitmay be varied as desired and aneffect similar to feathering 'of a friction clutch may be obtained.

Reverse operation of the'v vehicle is Aobtained by moving the 'gearshiftlever e5 to neutral position and krocking it upwardly'of the steeringcolumn, thereby to move theshift finger its out of engagement with forkvIES-and into engagement .withfork Ilot. If sleeve lisin either of itsengaged positions, it will be automatically cammed back toneutralposition by thev acti-on of the cam shaped portion |56 of thefinger 'les during' its movement into engagement with lthe fork |50.After the ringer |66 has been engaged with the fork` 50, swinging oftli'egear shift lever S counterclockwise of the "steering" column axiswillino've the idler gear 8b rearwardly of Fig` '1 and into mesh withgears et and ali, thereby establishing reverse drive condition ingearbox C. The operation of the underdrive mechanism B is exactlythesame in reverse as for forward speeds and a two speed reverseoperation may be obtained in the same manner except that the car speedat which the governor |63 operates Will be somewhat lower due to thefact that the reverse drive ratio is relatively low.

When the control mechanism is modified by the substitution of an enginedriven governor in place of the pedal |12 as is illustrated in Fig. 12of the drawings, the operation of the mechanism is substantially thesame for all conditions of operation except that the underdrive coil 2|is gradually energized by operation of the governor |91 upon speeding upof the vehicle motor and is gradually de-energized by operation of thegovernor when the vehicle is brought to a stop. When the vehicle is atrest, the switch |62' will be open, the governor |91 being adjusted sothat this will occur at idling speed of the engine, and thus anautomatic no-creep condition is achieved.

Thus it may be seen that I have provided an improved transmissionmechanism which is sim-- ple in construction and operation and whichdoes not require the acquisition of new driving technique. While onlyone of the many possible embodiments of the invention has beenillustrated and described in this application, it is desired to pointout that those skilled in the art will t enlarged slot in one of. saidmembers for receiving said element with suiicient clearance to permitshifting of said element back to 'neutral position without disturbing aselected speed ratio setting of said member ;V a slot in theother ofsaid members for receiving said element; and means operatively`associated with vsaid A'element for `compelling return of said firstmembertc neutral upon movement of said element from neutral position toengage said other'memb'ei'l '2.' In achangespeed transmission mechanismhaving a'pair of membersadapted for shifting'to a plurality of positionsfrom neutral thereby to establish a plurality of drives of differentspeed ratios Aand directions, a'shifter element; a 'slot in each of saidshiftable members for operably receiving said element; one of said slotsproviding suiiicient clearance'to permit return .of said element toneutral Without 'disturbinga speed ratioestablishing setting of therespective member'f a cam portion formed on said shifter element; andprojections formed 'on said` last member and adapted for engagement bysaid cam portion upon the movement of said element out of said slotwhereby said member is camrnedV back to neutral position. t t t 3. In avehicle transmission,V a pair of members adapted for selective shiftingto provide a plurality' of speed ratio drives; a shift element adaptedfor rocking in one plane to selectively engage said members and forlrocking lin a second plane to shift the members; a slot in each of saidmembers for receiving said element, one of said slots being elongatedsuch that when the member having the same is engaged by said element thelatter may be returned to neutral position while the engaged memberremains in a shifted position; and means operable in response to rockingof the element to engage the other yof said pair of members forcompelling return of the first of said pair of members to neutralposition.

4. In a vehicle transmission, a pair of members adapted for selectiveshifting to provide a plurality of speed ratio drives; a shift elementadapted for rocking in one plane to selectively 'engage said members andfor rocking in a second plane to shift the members; a slot in each ofsaid members for receiving said element, one of said slots beingelongated such that said element may be returned to neutral positionwhile the engaged member remains in a shifted position; and cam meanscarried by said element for camming said engaged member back to neutralposition in response to rocking of said element in said one plane.

5.' In a change speed transmission mechanism having a pair of membersadapted for shifting from an initial position to a secondary positionthereby to establish a plurality of speed ratio drives, a shifterelement, means on one of said members for operably receiving saidshifter element, a slot on the second of said members for operablyreceiving said shifter element, said slot providing sufficient clearanceto permit return of said shifter element to the initial position of saidsecond member following shift of said second member to its secondaryposition, and while said second member remains in its speed ratioestablishing setting in said secondary position, and cam means on saidshifter element and second member engageable upon movement of saidshifter element out of said slot, for compelling return of said secondmember to its initial position before shifting of said first member bysaid shifter element.

6. In a change speed transmission mechanism, first and second shiftablemembers adapted for selective shifting from an initial position to asecondary position to provide a plurality of speed ratio drives, a thirdmember for selectively engaging said first and second members forshifting the same, means mounting said third member for movement in alplane to engage the shiftable members and in another plane when shiftingsaid shiftable members, one of said first and third members havingspaced portions defining a slot for receiving the other of said iirstand third members upon movement of said third member in its plane ofengaging movement to engage said first member, one of said spacedportions on the member defining said slot coacting with a portion ofsaid other member upon movement of said third member in its plane ofshifting movement to shift said first member to its secondary positionto establish a drive setting in said position, and the other of saidspaced portions being spaced such a distance from the first mentionedspaced portion to accommodate ber in response to movement of said thirdmember in its plane of engaging movement to engage said second shiftablemember, for compelling return of said first shiftable member to itsinitial position before shifting the second shiftable member.

7. In a change speed transmission mechanism a member adapted forshifting from a first position to a second position to establish apredetermined speed ratio drive, a shift element mounted for movement ina plane between said iirst and second positions and in an intersectingplane between said first position and a third position, meansestablishing a lost motion connection between said member and shiftelement during movement of said member and shift element between saidiirst and second positions, said connection providing for shifting ofsaid member by said shift element from said first to said secondposition and for return of said shift element to said first positionWithout disturbing the drive establishing setting of said member in saidsecond position, and engageable means on said member and shift elementfor compelling return of said member to said first position uponmovement of said shift element in said intersecting plane from saidfirst to said third position following said return of said shift elementfrom said second to said first position.

HENRY W. GILFILLAN.

